:root { --primary: #0066FF; --primary-hover: #0052CC; --primary-light: #E6F0FF; --text-main: #1A1A1A; --text-sub: #5C6C80; --bg-white: #FFFFFF; --bg-gray: #F5F8FF; --bg-footer: #111827; --border: #E2E8F0; --radius-sm: 8px; --radius-md: 12px; --radius-lg: 20px; --container: 1160px; --shadow-sm: 0 2px 8px rgba(0,0,0,0.04); --shadow-md: 0 8px 24px rgba(0,102,255,0.08); --shadow-lg: 0 12px 32px rgba(0,0,0,0.08); }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body { font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text-main); background: var(--bg-white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
    a { color: var(--primary); text-decoration: none; transition: color 0.2s; }
    a:hover { color: var(--primary-hover); }
    ul { list-style: none; }
    img, svg { max-width: 100%; display: block; height: auto; }
    .container { width: min(100% - 40px, var(--container)); margin-inline: auto; }

    .btn { display: inline-flex; align-items: center; justify-content: center; padding: 0 24px; height: 44px; border-radius: var(--radius-sm); font-size: 15px; font-weight: 600; cursor: pointer; transition: all 0.2s; border: 1px solid transparent; white-space: nowrap; }
    .btn-primary { background: var(--primary); color: #fff; box-shadow: 0 4px 12px rgba(0,102,255,0.2); }
    .btn-primary:hover { background: var(--primary-hover); color: #fff; transform: translateY(-1px); }
    .btn-outline { background: #fff; color: var(--primary); border-color: var(--primary); }
    .btn-outline:hover { background: var(--primary-light); }
    
    .header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.92); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
    .header-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
    .logo img { height: 40px; width: auto; }
    .nav-links { display: flex; gap: 32px; }
    .nav-links a { color: var(--text-main); font-size: 15px; font-weight: 500; }
    .nav-links a:hover, .nav-links a.active { color: var(--primary); }

    .section { padding: 80px 0; }
    .section-gray { background: var(--bg-gray); }
    .section-header { margin-bottom: 48px; text-align: center; width: 100%; }
    .section-header h2 { font-size: 32px; font-weight: 800; color: #0B1A30; margin-bottom: 16px; line-height: 1.3; }
    .section-header p { color: var(--text-sub); font-size: 16px; line-height: 1.75; }

    /* Hero */
    .hero { padding: 80px 0 60px; background: linear-gradient(135deg, #F8FAFF 0%, #E6F0FF 100%); text-align: center; }
    .hero h1 { font-size: clamp(32px, 4vw, 52px); font-weight: 800; color: #0B1A30; margin-bottom: 20px; letter-spacing: -1px; }
    .hero p { font-size: 18px; color: var(--text-sub); }
    .version-tag { display: inline-flex; align-items: center; gap: 8px; background: #fff; border: 1px solid var(--border); padding: 6px 14px; border-radius: 999px; font-size: 13px; font-weight: 600; color: #10B981; margin-bottom: 24px; box-shadow: var(--shadow-sm); }
    
    /* H2 1: 下载卡片 */
    .grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; width: 100%; }
    .download-card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 40px 24px; display: flex; flex-direction: column; align-items: center; transition: all 0.3s; }
    .download-card:hover { border-color: var(--primary); transform: translateY(-6px); box-shadow: var(--shadow-lg); }
    .download-card-icon { width: 64px; height: 64px; background: var(--bg-gray); border-radius: 18px; display: flex; align-items: center; justify-content: center; margin-bottom: 24px; }
    .download-card-icon svg { width: 32px; height: 32px; fill: var(--primary); }
    .download-card h3 { font-size: 18px; margin-bottom: 8px; color: var(--text-main); font-weight: 700; text-align: center; }
    .download-details { font-size: 13px; color: var(--text-sub); margin-bottom: 24px; text-align: center; line-height: 1.5; }
    .download-details span { display: block; }
    .download-card .btn { margin-top: auto; width: 100%; }
    .pricing-link { display: block; text-align: center; margin-top: 32px; font-size: 15px; font-weight: 600; }

    /* H2 2: 系统要求表格 */
    .table-responsive { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius-md); background: #fff; box-shadow: var(--shadow-sm); width: 100%; }
    table { width: 100%; border-collapse: collapse; text-align: center; min-width: 700px; }
    th, td { padding: 18px 20px; border-bottom: 1px solid var(--border); }
    th { background: var(--bg-gray); font-weight: 700; color: var(--text-main); font-size: 15px; }
    td { font-size: 14px; color: var(--text-sub); }
    td strong { color: var(--text-main); }

    /* H2 3: 安装指南 */
    .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; width: 100%; }
    .step-card { background: #fff; padding: 32px; border-radius: var(--radius-md); border: 1px solid var(--border); position: relative; }
    .step-num { width: 40px; height: 40px; background: var(--primary-light); color: var(--primary); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 18px; font-weight: 800; margin-bottom: 20px; }
    .step-card h3 { font-size: 18px; margin-bottom: 12px; }
    .step-card p { font-size: 15px; color: var(--text-sub); line-height: 1.7; }

    /* H2 4: 防伪校验 */
    .verify-box { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 40px; display: flex; align-items: center; gap: 40px; width: 100%; }
    .verify-box-icon { width: 80px; height: 80px; background: #E8F5E9; color: #10B981; border-radius: 50%; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
    .verify-box-content h3 { font-size: 22px; margin-bottom: 12px; color: var(--text-main); }
    .verify-box-content p { font-size: 15px; color: var(--text-sub); line-height: 1.8; margin-bottom: 16px; }
    .verify-list { display: grid; gap: 8px; }
    .verify-list li { font-size: 14px; color: var(--text-main); display: flex; align-items: flex-start; gap: 8px; }
    .verify-list li::before { content: '✓'; color: #10B981; font-weight: bold; }

    /* H2 5: FAQ */
    .faq-list { width: 100%; display: flex; flex-direction: column; gap: 16px; }
    details { background: #fff; border: 1px solid var(--border); border-radius: var(--radius-md); width: 100%; }
    summary { padding: 24px 32px; font-size: 17px; font-weight: 600; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; }
    summary::-webkit-details-marker { display: none; }
    summary::after { content: '+'; font-size: 24px; color: var(--text-sub); font-weight: 400; }
    details[open] summary::after { content: '−'; color: var(--primary); }
    details p { padding: 0 32px 24px; color: var(--text-sub); font-size: 15px; line-height: 1.8; }
    details h3 { font-size: 17px; font-weight: 600; margin: 0; }

    /* Footer */
    .footer { background: var(--bg-footer); color: #94A3B8; padding: 80px 0 32px; }
    .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 64px; }
    .footer-brand img { height: 40px; margin-bottom: 20px; }
    .footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 24px; }
    .footer-col a { color: #94A3B8; font-size: 14px; display: block; margin-bottom: 12px; }
    .footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 32px; display: flex; justify-content: space-between; font-size: 13px; }

    @media (max-width: 1024px) {
      .grid-4, .grid-3 { grid-template-columns: repeat(2, 1fr); }
      .verify-box { flex-direction: column; text-align: center; gap: 24px; }
      .verify-list li { justify-content: center; text-align: left; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .grid-4, .grid-3 { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; text-align: center; }
      .footer-brand p { margin: 0 auto; }
      .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
      summary { padding: 20px 24px; font-size: 16px; }
      details p { padding: 0 24px 24px; }
    }